Pregnancy-related widening and thinning of the belly muscles may reduce the effectiveness of tummy tuck (abdominoplasty) surgery, researchers found. This is especially true in women who've had multiple pregnancies.

But Dr. Gregory Dumanian and colleagues at Northwestern Memorial Hospital in Chicago said there may be a fix.

In certain cases, an alternative approach that follows the principles of hernia repair may be successful, the researchers found.

The study authors described and showed this approach in an online video and case examples of two women with recurrent bulging of the abdominal wall after tummy tuck surgery.

"This technique may be indicated for a minority of patients," Dumanian and his co-authors concluded. They said evaluation of muscle width during surgery may avoid patient dissatisfaction and revision procedures.

For the study, the researchers examined abdominal CT scans of 60 women, aged 18 to 45, to assess pregnancy-related changes in the rectus muscles that run along each side of the abdomen. The muscles are separated by a band of fibrous tissue called the linea alba.

Pregnancy was associated with widening of the rectus muscles. The average width was 2.4 inches in women who'd never been pregnant, 2.6 inches after one pregnancy, and 2.8 inches after three or more pregnancies.

The study also found widening of the linea alba after pregnancy. But there was no additional widening after multiple pregnancies.

The report was published in the August issue of the journal Plastic and Reconstructive Surgery.

Tummy tuck is one of the top five cosmetic plastic surgery procedures in the United States. More than 130,000 were performed in 2018, according to the American Society of Plastic Surgeons.